typedef volatile unsigned int u32;

#define PA_CFG1 (*(u32 *)0x01c20804)
#define PA_DATA (*(u32 *)0x01c20810)

void delay(int val)
{
    val *= 0xffff;

    while(val--);

}

void _start()
{
    int i;

    PA_CFG1 &= ~(7<<28);
    PA_CFG1 |= 1<<28;

    for (i=0;i<100;i++)
    {
        PA_DATA |=1<<15;
        delay(1000);

        PA_DATA &= ~(1<<15);
        delay(1000);
    }

}